Target enrichment prior to next-generation sequencing is more cost-effective than whole genome, whole exome, and whole transcriptome sequencing and therefore more practical for broad implementation; both for research discovery and clinical applications. For example, high coverage depth afforded by target enrichment approaches enables a wider dynamic range for allele counting (in gene expression and copy number assessment) and detection of low frequency mutations, a critical feature for evaluating somatic mutations in cancer. Examples of current enrichment protocols for next generation sequencing include hybridization-based capture assays (TruSeq Capture, Illumina; SureSelect Hybrid Capture, Agilent) and polymerase chain reaction (PCR)-based assays (HaloPlex, Agilent; AmpliSeq, Ion Torrent; TruSeq Amplicon, Illumina; emulsion/digital PCR, Raindance). Hybridization-based approaches capture not only the targeted sequences covered by the capture probes but also near off-target bases that consume sequencing capacity. In addition, these methods are relatively time-consuming, labor-intensive, and suffer from a relatively low level of specificity. A PCR amplification based approach is simpler and faster but by conventional design requires the use of both forward and reverse primers flanking the target loci. In particular, for detection of genomic rearrangements with unknown fusion partners, PCR is not applicable.